问答

1答疑

[Reading Comprehension]

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文章：

Line         A small number of the forest species of
  lepidoptera (moths and butterflies, which exist as
  caterpillars during most of their life cycle) exhibit
  regularly recurring patterns of population growth
(5) and decline—such fluctuations in population are
  known as population cycles. Although many different
  variables influence population levels, a regular pattern
  such as a population cycle seems to imply a
  dominant, driving force. Identification of that driving
(10) force, however, has proved surprisingly elusive
  despite considerable research. The common
  approach of studying causes of population cycles by
  measuring the mortality caused by different agents,
  such as predatory birds or parasites, has been
(15) unproductive in the case of lepidoptera. Moreover,
  population ecologists’ attempts to alter cycles by
  changing the caterpillars’ habitat and by reducing
  caterpillar populations have not succeeded. In short,
  the evidence implies that these insect populations, if
(20) not self-regulating, may at least be regulated by an
  agent more intimately connected with the insect than
  are predatory birds or parasites.
       Recent work suggests that this agent may be a
  virus. For many years, viral disease had been reported
(25) in declining populations of caterpillars, but population
  ecologists had usually considered viral disease to
  have contributed to the decline once it was underway
  rather than to have initiated it. The recent work has
  been made possible by new techniques of molecular
(30) biology that allow viral DNA to be detected at low
  concentrations in the environment. Nuclear
  polyhedrosis viruses are hypothesized to be the
  driving force behind population cycles in lepidoptera
  in part because the viruses themselves follow an
(35) infectious cycle in which, if protected from direct
  sun light, they may remain virulent for many years
  in the environment, embedded in durable crystals of
  polyhedrin protein. Once ingested by a caterpillar,
  the crystals dissolve, releasing the virus to infect
(40) the insect’s cells. Late in the course of the infection,
  millions of new virus particles are formed and
  enclosed in polyhedrin crystals. These crystals
  reenter the environment after the insect dies and
  decomposes, thus becoming available to infect
(45) other caterpillars.
       One of the attractions of this hypothesis is its broad
  applicability. Remarkably, despite significant differences
  in habitat and behavior, many species of lepidoptera
  have population cycles of similar length, between eight
(50) and eleven years. Nuclear polyhedrosis viral infection is
  one factor these disparate species share.


题目：

It can be inferred from the passage that the mortality caused by agents such as predatory birds or parasites was measured in an attempt to

选项:

A、develop an explanation for the existence of lepidoptera population cycles
B、identify behavioral factors in lepidoptera that affect survival rates
C、identify possible methods for controlling lepidoptera population growth
D、provide evidence that lepidoptera populations are self-regulating
E、determine the life stages of lepidoptera at which mortality rates are highest

答案:

A
1答疑

[Data Sufficiency]

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题目：

If x 0, is ﹤1?
(1)  x ﹤1
(2)  x﹥−1
Ÿ

选项:

答案:

C
1答疑

[Two-part Analysis]

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题目：

Professor A: The aid industry should begin to limit its efforts to spending on primary schools in the poorest areas, providing medicines and other basic supplies for health care such as mosquito nets, and to a few key agricultural initiatives.
Professor B: Much education work has been ineffective. A village or town with poor schooling may be better off getting a road than a teacher. Once local farmers can transport produce to market they will be willing to pay for schools-and to make sure the schools succeed.
Suppose that the professors’ statements express their genuine opinions. Select statements (1) and (2) as follows: Professor A would likely disagree with (1) and Professor B would take (2) to present logical support for (1).Select only two statements, one per column.

选项:

A、The aid industry should focus less on the areas of health and agriculture than it now does.
B、The aid industry should focus more on primary education than it now dose.
C、The aid industry should focus its spending less on primary education than it now dose.
D、Projects in health and agriculture are more likely to be successful if they not paid for by the aid industry.
E、Projects in education are more likely to be successful if they are paid by the aid industry.
F、Projects in education are more likely to be successful if they are paid by local people

答案:

C F
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[Problem Solving]

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题目：

On a scale that measures the intensity of a certain phenomenon, a reading of n + 1 corresponds to an intensity that is 10 times the intensity corresponding to a reading of n. On that scale, the intensity corresponding to a reading of 8 is how many times as great as the intensity corresponding to a reading of 3?

选项:

A、5
B、50
C、105
D、510
E、810 ‒ 310

答案:

C
1答疑

[Data Sufficiency]

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题目：

If r and s are positive integers, is r/s an integer?
(1)Every factor of s is also a factor of r.
(2)Every prime factor of s is also a prime factor of r.

选项:

A、Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B、Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C、BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D、EACH statement ALONE is sufficient.
E、Statements (1) and (2) TOGETHER are NOT sufficient.

答案:

A
1答疑

[Sentence Correction]

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题目：

While all states face similar industrial waste problems, the predominating industries and the regulatory environment of the states obviously determines the types and amounts of waste produced, as well as the cost of disposal.

选项:

A、all states face similar industrial waste problems, the predominating industries and the regulatory environment of the states obviously determines
B、each state faces a similar industrial waste problem, their predominant industries and regulatory environment obviously determine
C、all states face a similar industrial waste problem; their predominating industries and regulatory environment obviously determines
D、each state faces similar industrial waste problems, the predominant industries and the regulatory environment of each state obviously determines
E、all states face similar industrial waste problems, the predominant industries and the regulatory environment of each state obviously determine

答案:

E
1答疑

[Sentence Correction]

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题目：

Using technology as new as space-age fabrics and as ordinary as common dry-cleaning chemicals, scientists and historians, in their attempt at cleaning and preserving the American flag that flew over Fort McHenry in Baltimore in 1814, are hoping that it will then last another 200 years.

选项:

A、and as ordinary as common dry-cleaning chemicals, scientists and historians, in their attempt at cleaning and preserving the American flag that flew over Fort McHenry in Baltimore in 1814, are hoping
B、and as ordinary as common dry-cleaning chemicals, scientists and historians are attempting to clean and preserve the American flag that flew over Fort McHenry in Baltimore in 1814, hoping
C、and as ordinary as common dry-cleaning chemicals, an attempt by scientists and historians to clean and preserve the American flag that flew over Fort McHenry in Baltimore in 1814 is being made in the hope
D、but also as ordinary as common dry-cleaning chemicals, scientists and historians who are attempting to clean and preserve the American flag that flew over Fort McHenry in Baltimore in 1814, hoping
E、 but also as ordinary as common dry-cleaning chemicals, an attempt by scientists and historians at cleaning and preserving the American flag that flew over Fort McHenry in Baltimore in 1814 in hopes

答案:

B
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[Sentence Correction]

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题目：

The type of behavior exhibited when an animal recognizes itself in a mirror comes within the domain of “theory of mind,” thus is best studied as part of the field of animal cognition.

选项:

答案:

D
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[Critical Reasoning]

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题目：

Which of the following most logically completes the passage?

It is generally believed that people receiving frequent medical checkups are likely to need hospitalization less frequently than they would otherwise; after all, many things can be done following a checkup to prevent problems that, if ignored, might become acute and then require hospitalization. But for people with chronic illnesses, frequent medical checkups are likely to lead to more frequent hospitalization since __________.

选项:

答案:

A
1答疑

[Reading Comprehension]

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文章：

The United States hospital industry is an unusual market in that nonprofit and for-profit producers exist simultaneously. Theoretical literature offers conflicting views on whether nonprofit hospitals are less financially efficient. Theory suggests that nonprofit hospitals are so much more interested in offering high-quality service than in making money that they frequently input more resources to provide the same output of service as for-profit hospitals. This priority might also often lead them to be less vigilant in streamlining their services--eliminating duplication between departments, for instance. Conversely, while profit motive is thought to encourage for-profit hospitals to attain efficient production, most theorists admit that obstacles to that efficiency remain. For-profit hospital managers, for example, generally work independently of hospital owners and thus may not always make maximum financial efficiency their highest priority. The literature also suggests that widespread adoption of third-party payment systems may eventually eliminate any such potential differences between the two kinds of hospitals.

The same literature offers similarly conflicting views of the efficiency of nonprofit hospitals from a social welfare perspective. Newhouse (1970) contends that nonprofit hospital managers unnecessarily expand the quality and quantity of hospital care beyond the actual needs of the community, while Weisbrod (1975) argues that nonprofit firms--hospitals included--contribute efficiently to community welfare by providing public services that might be inadequately provided by government alone.

题目：

The passage suggests which of the following about the managers mentioned in the highlighted text?

选项:

A、 They have generally been motivated to streamline hospital services as a result of direct intervention by hospital owners.
B、 They are more likely than managers of nonprofit hospitals to use unnecessary amounts of resources to provide services.
C、 Their most important self-acknowledged goal is to achieve maximum financial efficiency so that hospitals show a profit.
D、 Their decisions regarding services provided by their hospitals may not reflect hospital owners' priorities.
E、 They do not place a high priority on maximizing profits, despite their desire to achieve efficiency.

答案:

D
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1933浏览

[Undefined]

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Art historian: Unlike many artistic traditions that sought to depict plants native to the local area in a seasonally appropriate way (for example, depicting scenes of spring with the plants in the appropriate stages of development for that season), seventeenth-century Dutch artists specializing in flower paintings almost exclusively chose to depict exotic species of flowers from outside the local area. Painting such species was worthwhile primarily because the art-buying public had developed a strong preference for images of the exotic. The great botanical centers of the time gave the artists direct access to such flowers, which the artists would freely combine in a single painting, regardless of whether the combined species occurred together in the wild, and depicted each in full bloom, regardless of whether those species bloomed at the same time in nature.

Statement: The art historian makes the point that the species of flowers these Dutch artists chose to paint were 1 largely because the species were 2 .

Select for 1 and for 2 the options that complete the statement so that it is most strongly supported by the information provided. Make only two selections, one in each column.
我选的CE，和EC有什么区别？怎么选出EC的？
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5023浏览

[Undefined]

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An unusually severe winter occurred in Europe after the continent was blanketed by a blue haze resulting from the eruption of the Laki Volcano in the European republic of Iceland in the summer of 1984.  Thus, it is evident that major eruptions cause the atmosphere to become cooler than it would be otherwise.
Which of the following statements, if true, most seriously weakens the argument above?
C选项为什么就不会有张冠李戴的问题呢，1984和1982的气候情况能一样吗，C里的火山就可以试用于原文的火山吗
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5707浏览

[Undefined]

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The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present. If the concentration of chemical B is increased by 100 percent, which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?
为什么这个题一定是相乘不能是相加呢？y=k1A方-k2B （k1,k2大于0 ），也满足题目说的与A方成正比与B成反比啊？但是这道题只有相乘的情况才能选出正确答案
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1912浏览

[Undefined]

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Tiger beetles are such fast runners that they can capture virtually any nonflying insect.  However, when running toward an insect, the beetles intermittently stop, and then, a moment later, resume their attack.  Perhaps they cannot maintain their pace and must pause for a moment's rest; but an alternative hypothesis is that while running tiger beetles are unable to process the resulting rapidly changing visual information, and so quickly go blind and stop.
 
Which of the following, if discovered in experiments using artificially moved prey insects, would support one of the two hypotheses and undermine the other?
答案C是怎么支持一个猜想又削弱另一个猜想的？
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4131浏览

[GWD]

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The author of the passage implies that which of the following is a possible partial explanation for acquisition behavior during the 1970's and 1980's?
请解释这道题为什么不选C或E，除了正确选项B，我认为文中也正确地提到了这两个选项可以解释acquisition behavior during 1970s and 80s
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2898浏览

[OG]

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The primary purpose of the passage is to
为什么选E不选B
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1915浏览

[Undefined]

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Club X has more than 10 but fewer than 40 members. Sometimes the members sit at tables with 3 members at one table and 4 members at each of the other tables, and sometimes they sit at tables with 3 members at one table and 5 members at each of the other tables. If they sit at tables with 6 members at each table except one and fewer than 6 members at that one table, how many members will be at the table that has fewer than 6 members?
提问小梅老师 这道题求讲一下 我没什么思路 带入数字得的是3
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2003浏览

[Undefined]

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A photography dealer ordered 60 Model X cameras to be sold for $250 each, which represents a 20 percent markup over the dealer's initial cost for each camera. Of the cameras ordered, 6 were never sold and were returned to the manufacturer for a refund of 50 percent of the dealer's initial cost. What was the dealer's approximate profit or loss as a percent of the dealer's initial cost for the 60 cameras?
请问小梅老师 这道题讲讲一下 我算的是19% 原来成本是200每个 亏了6个 每个亏100. 最后得不出答案
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427151浏览

[Undefined]

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Analytical!
请问may老师，这题该用什么思路来做？
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434289浏览

[Undefined]

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Analytical!
请问张老师，这道题为什么D不对？我有我觉得second paragraph最后一句话特别指向D
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